It is thought that the virus was introduced to chickens through a vaccine that had been grown in contaminated duck-embryo fibroblasts. The virus became established in chickens, causing substantial problems with egg shell quality and loss of eggs.

Yes, in the german poultry forum there is an user, who made experience with EDS - as far as I know in show breeds. She has a mixed flock of different breeds and don't hatch, so it came into her flock by a purchase. She vaccinates against EDS since then.

The paper is mostly about chicken meat processing workers (whether any human risks from avian viruses such as Mareks, Avian Leukosis, REV). It also touches on the history of human vaccine contaminants (from chicken embryo developed vaccines):

Quote:

Moreover, humans vaccinated with exogenous or endogenous ALV-contaminated vaccines against yellow fever, measles, and mumps did not become antibody- or virus-positive for ALV. The risks for human infection with REV are similarly limited......

And about the Marek's virus (MDV)

Quote:

....MDV is typically associated with infection of chickens, and almost all experimental data show that MDV cannot infect mammalian cells or animals, including nonhuman primates. One study reports the presence of MDV gD DNA in human sera, but this finding could not be confirmed by another group.

Common antigenicity has been discovered between glycoprotein antigens obtained from leukotic lesions of chickens with Marek’s disease and antigens obtained from a variety of human cancers. This suggests that Marek’s disease herpesvirus is a possible etiological agent in human cancer.

So - if the Marek virus can be considered as possible reason of human cancer it should prick up your ears because in the last 40 years the virulence has multiplied - by the vaccines itself. Nevertheless vaccination is still considered as the best way for food safety:

“Food chain security and everything rests on vaccines. They are the most successful and cheapest public health interventions that we’ve ever had. We just need to consider the evolutionary consequences of these ones with leaky transmission.”

Who knows why there are so many cancer patients today? Meat consumption per se has been repeatedly discussed, but perhaps it is especially Marek-contaminated meat (under the vaccine coverage)?